Talc-molybdenite separation

ABSTRACT

A method of enriching the molybdenite fraction of ores and concentrates having hydrophobic silicates containing magnesium such as talc. An aqueous slurry of the ore or concentrate is treated with a water soluble metallic salt of a weak base and strong acid and a water soluble salt of a weak acid and subjected to agitation. The treated pulp is then subjected to a conventional froth flotation wherein a molybdenite fraction is floated off as molybdenite enriched concentrate and a talc fraction is depressed into the tailings.

United States Patent Huch et al. 1 Nov. 25, 1975 [54] TALC-MOLYBDENITE SEPARATION 19,374 9/1915 United Kingdom 209/167 [751 Richard 0: Huch; Pedro vanes, 523131; 251332 iilslijiiiijiiiiii.. 135331123 Appl Field Assignee:

Filed:

both of Tucson, Ariz.

Pima Mining Company, Los Angeles, Calif.

Sept. 27, 1973 Related US. Application Data Continuation-impart of Ser. No. 216,723, Jan. 10,

abandoned.

US. Cl. 209/167 Int. Cl.

B03D l/06 of Search 209/166, 167

References Cited UNITED STATES PATENTS 7/1914 Greenway 209/167 11/1921 Robbins.... 9/1941 Janney 12/1949 Nokes... 12/1952 Allen 4/1967 Bloom 209/167 4/1932 Australia 209/166 OTHER PUBLICATIONS 50th Anniv. Vo1., Froth Flotation, 1962, 393398.

Chem. Abstracts, Vol. 69, 1968, 98563 h.

Chem. Abstracts, Vol. 69, 1968, 10208, 108806 f.

Chem Abstracts, Vol. 71, 1969, 23841 e.

Primary Examiner--Robert l-Ialper Attorney, Agent, or Firm-Elwood S. Kendrick [57] ABSTRACT A method of enriching the molybdenite fraction of ores and concentrates having hydrophobic silicates containing magnesium such as talc. An aqueous slurry of the ore or concentrate is treated with a water soluble metallic salt of a weak base and strong acid and a water soluble salt of a weak acid and subjected to agitation. The treated pulp is then subjected to a conventional froth flotation wherein a molybdenite fraction is floated off as molybdenite enriched concentrate and a talc fraction is depressed into the tailings.

22 Claims, N0 Drawings TALC-MOLYBDENITE SEPARATION This application is a continuation-in-part of our copending patent Application Ser. No. 216,723, now abandoned, filed Jan. 10, 1972.

BACKGROUND OF THE INVENTION This invention is directed to a process for separating hydrophobic silicates containing magnesium known as talc for molybdenite bearing ores and concentrates. In particular this invention is directed to a flotation process for molybdenite ores and concentrates where a hydrophobic talc fraction is depressed and the molybdenite fraction is selectively floated away therefrom.

Lack of a commercial process emphasizes the difficulty of selectively floating molybdenite from molybdenite bearing concentrates having hydrophobic silicates containing magnesium such as talc. Organic colloids or organic dyes have been used for the upgrading of molybdenite concentrates and ores, but in such applications both the molybdenite and the contaminants could be depressed. ,The presence of tale is undesirable because it complicates the further treatment of molybdenite.

The effective commercial methods for upgrading molybdenite from molybdenite bearing concentrates having hydrophobic silicates containing magnesium are those related to the Utah Process whereby bulk molybdenite bearing concentrates are either roasted or spray dried to render the molybdenum less floatable than acid insoluble contaminants including hydrophobic silicates containing magnesium. These contaminants are then floated leaving a molybdenite enriched tailing.

These processes require expensive and elaborate systems of multiple hearth roasters or spray dryers with adequate dust collecting systems. Temperature, retention time, and degree of oxidation of the minerals are very critical. The expenditure of energy for heat and transportation of the ore concentrate is costly. The roasting process has been used at the Pima Mining Company, on final molybdeniteconcentrates. Other properties use more bulky concentrates from the initial stages of their molybdenite recovering plants.

SUMMARY OF THE INVENTION The present process consists of treating pulps of molybdenite bearing concentrates having a substantial amount of hydrophobic silicates containing magnesium by agitation in the presence of a water soluble metallic salt of a weak base and a strong acid and a water soluble salt of a weak acid. The treated pulp is then subjected to a conventional froth flotation wherein a molybdenite fraction is floated off as a molybdenite enriched concentrate and hydrophobic silicate containing magnesium, such as talc, is depressed into the tailings.

The subject process is useful in that there is'sufficient depression of hydrophobic silicates containing magnesium, so that either a marketable grade of molybdenite concentrate is produced directly or the molybdenite concentrate is enriched so that subsequent processing is facilitated.

DESCRIPTION-OF THE INVENTION The present process is practiced by preparing aqueous slurry or pulp of ground molybdenite concentrate or a molybdenite bearing ore. Generally the concentrated ore is ground to minus mesh, preferably minus 48 mesh. The pulp density varies between about 2 l% and about 45% solids; however, our tests of the process indicate that a more satisfactory separation is obtained at 5% to 15% solids.

The pulp is then treated with a water-soluble metallic salt of a weak base and a strong acid and a water-soluble salt of a weak acid. Between about 1 and about 30 pounds of the metallic salt of the weak base and strong acid are used per each ton of solids. Between about 1 and about 45 pounds of the salt of the weak acid are used per ton of solids. Optimum salt concentrations are dependent upon pulp conditions and salt combinations.

Best results are usually obtained if the pulp is treated first with the metallic salt of a weak base and a strong acid and then followed by the addition of the salt of a weak acid prior to flotation. However, satisfactory results can be obtained when the salt of a weak acid is added first, followed by the addition of the metallic salt of a weak base and a strong acid; both salts are added simultaneously; or both salts are premixed and then added to the pulp.

The preferred metallic salts of a weak base and strong acids are the water-soluble sulfate, nitrate, fluoride and chloride salts of aluminum, manganese, calcium, magnesium, zinc, copper, cobalt, nickel, chromium, iron and cadmium.

Typical salts of weak acids that can be employed in the present process include the water-soluble alkali metal (especially sodium and potassium), ammonium, and alkaline earth metal (especially calcium and magnesium) salts of silicic acids; carbonic acid; acids of phosphorus, including phosphoric acid, hypophosphorous acid, phosphorous acid, hypophosphoric acid and the like; the acids of boron, including ortho-boric acid, meta boric acid, tetraboric acid and the like; and hydroferrocyanic acid but only when the aforesaid metallic salt is a water-soluble salt of zinc. It will be appreciated by reference to chemical handbooks that not all of the possible combinations of the above are water-soluble.

The pulp and salts are agitated for a period of from about 1 minute to about 60 minutes, preferably about 30 minutes. Then the pulp. is subject to a conventional froth flotation for about 1 to about 30 minutes. The molybdenite fraction is floated off as an enriched molybdenite concentrate. The molybdenite recovery is very high, from about to about 96% and the concentrate can be enriched by a factor of about 2 to about 5 times. The hydrophobic silicates fraction and other acid insoluble contaminants are depressed into the tailings (from about 50 to about of the acid insoluble contaminants, principally talc and other hydrophobic silicates, are depressed into the tailings).

The following examples are intended to further illustrate the present invention and not intended as limitations thereof. Naturally the process conditions such as process times, temperature, pH and reagent concentration can be varied through routine experimentation to optimize the end results for a particular ore, mesh size, pulp density, and particular reagents employed.

EXAMPLE 1 (NO TREATING AGENT) A composite sample of low grade molybdenite concentrate produced at the Pima Mine containing approximately 18% molybdenite, 4% chalcopyrite, 5% pyrite and 69% acid insoluble minerals was made into a dilute pulp of five percent solids in water at ambient temperature in a laboratory flotation cell. A major portion of the said acid insoluble minerals was a hydrophobic silicate containing magnesium, i.e., talc. The pulp was immediately subjected to froth flotation and the froth removed for five minutes, during which a concentrate was separated. This example is given to exemplify the response of the composite sample without treatment by our new process. The results of the example are presented in the following table.

Distribution Weight Percent Percent Product Percent Mo lnsol. Mo lnsol.

Head 100.00 10.98 68.8 100.0 100.0 Concentrate 93.75 11.35 68.9 96.9 3.9 Tailing 6.25 5.47 66.7 3.1 6.1

EXAMPLE 2 Distribution Weight Percent Percent Product Percent Mo lnsol. Mo lnsol.

Head 100.00 10.98 67.7 100.0 100.0 Concentrate 44.69 22.53 49.7 89.0 32.8 Tailing 55.31 2.24 82.2 11.0 67.2

EXAMPLE 3 Still another sample of the same composite described in example 1 was subjected to the pulping procedure described in example 1. A quantity of sodium silicate corresponding to 7.5 pounds per ton of solids was added to the pulp. A quantity of zinc sulfate corresponding to 16 pounds per ton of solids was then added to the pulp. The pulp was agitated for thirty minutes and then subjected to flotation as described in example 1. The results are presented in the following table.

Distribution Weight Percent Percent Product Percent Mo lnsol. Mo lnsol.

Head 100.00 10.99 67.5 100.0 100.0 Concentrate 54.08 19.03 55.1 93.6 44.1 Tailing 45.92 1.53 82.2 6.4 55.9

EXAMPLE 4 A sample of the composite described in example 1 was subjected to the pulping procedure described in example l. A quantity of sodium silicate solution was placed in a beaker. To this was added a quantity of 10% zinc sulfate solution. The contents in the beaker were then washed into the pulp. The quantity of sodium silicate corresponded to 7.5 pounds per ton of solids; the quantity of zinc sulfate corresponded to 1 6 pounds per ton of solids. The pulp was agitated for thirty min- 4 utes and then subjected to flotation as described in example l. The results are presented in the following table.

Distribution Weight Percent Percent Product Percent Mo lnsol. Mo lnsol.

Head 100.0 11.10 68.2 100.0 100.0 Concentrate 56.61 18.12 58.0 92.4 48.1 Tailing 43.39 1.95 81.6 7.6 51.9

EXAMPLE 5 A sample of the composite described in example 1 was subjected to the pulping procedure described in example 1. The pulp was then agitated with a quantity of zinc sulfate corresponding to 16 pounds per ton of solids for thirty minutes. An addition of disodium hydrogen phosphate corresponding to 7.5 pounds per ton of solids was then added. The pulp was then subjected to flotation as described in example 1. The results are presented'in the following table.

- Distribution Weight Percent Percent Product Percent Mo lnsol. Mo. lnsol.

Head 100.0 10.97 68.1 100.0 100.0 Concentrate 35.56 28.58 40.1 92.6 20.9 Tailing 64.44 1.26 83.6 7.4 79.1

EXAMPLE 6 A sample of the composite described in example 1 was subjected to the pulping procedure described in example 1. The pulp was then agitated with a quantity of zinc sulfate corresponding to 16 pounds per ton of solids for thirty minutes. An addition of sodium acid carbonate corresponding to 7.5 pounds per ton of solids was then added. The pulp was then subjected to flotation as described in example 1. The results are presented in the following table.

Distribution Weight Percent Percent Product Percent Mo lnsol. Mo lnsol.

Head 100.00 1 1.66 67.6 100.0 100.0 Concentrate 33.94 32.56 35.2 94.8 17.7 Tailing 66.06 0.92 84.2 5.2 82.3

EXAMPLE 7 A sample of the composite described in example 1 was subjected to the pulping procedure described in example 1. A quantity of 10% sodium silicate solution was placed in a beaker. To this was added a quantity of 10% aluminum sulfate solution. The contents in the beaker were then washed into the pulp. The quantity of sodium silicate corresponded to 7.5 pounds per ton of solids; the quantity of aluminum sulfate corresponded to six pounds per ton of solids. The pulp was then agitated for thirty minutes and then subjected to flotation as described in example 1. The results are presented in the following table:

-continued Distribution Distribution Weight Percent Percent Weight Percent Percent Product Percent Mo lns l. M l l, Product Percent Mo lnsol. Mo lnsol. Head 100.00 10.52 68.3 100.0 I 100.0 Tailing 65-91 L 83.3 Concentrate 52.50 l7.59 58.0 87.8 44.6 Tailing 47.50 2.71 79.7 12.2 55.4

EXAMPLE ll EXAM 8 A sample of the composite described in example 1 A l f h was subjected to the pulping procedure described in exsaglp e g t E descnbed m f P 1 ample l. The pulp was then agitated with a quantity of was i R f}: to t e Pu pmg pr9cedure descnbed chromic sulfate corresponding to four pounds per ton r 6 Pulp was Qgltated with a quanmy of of solids for five minutes. A quantity of disodium hya umlfwm sulfate Q PW to F poLjndsPer drogen phosphate corresponding to 7.5 pounds per ton of sohds for five i u A Quantity of disodlum of solids was then added to the pulp. The pulp was then drogefl Phosphate correspondmg to Pounds Pf ton subjected to flotation as described in example 1. The of sohdswas h m -T P p was sublected results are presented in the following table. to flotation as descrlbed 1n example 1. The results are presented in the following table.

Distribution Weight Percent Percent Product Percent Mo lnsol. Mo lnsol. Distrlbutron Weight Percent Percent Head 100.00 1 1.34 69.4 100.0 100.0 Product Percen Mo lnsol. Mo lnsol- Concentrate 56.21 L 18.36 30.4 91.0 48.9 Head M000 1031 6&8 [0M 1000 Tarllng 43.79 2.32 81.0 9.0 51.1 Concentrate 42.45 2l.29 5L6 82.8 31.8 Tailing 57.55 3.26 81.5 17.2 68.2 I

EXAMPLE l2 A sample of the composite described in example 1 EXAMPLE 9 was subjected to the pulping procedure described in ex- A sample of the composite described in example 1 ample The pulp was then agitated with a quantity of was subjected to the pulping procedure described in ex- C romic Sulfate corresponding to four pounds per ton ample l. The pulp was then agitated with a quantity of of sol ds for five mmutes. A quannty of sodium ac d aluminum sulfate corresponding to one pound per ton caljbonate Correspondmg to PQ P 0f of solids for two minutes. A quantity of sodium acid 501195 was adfied the PPP- T P p was carbonate corresponding to 7 5 pounds per ton f sub ected to flotatlon as described in example 1. The solids was then added. The pulp was then subjected'to results are Presented the b l tableflotation as described in example 1. The results are 40 presented in the followmg table. Distribution Weight ,Perccnt Percent Product Percent Mo lnsol. Mo lnsol.

1 Distribution Head 100.00 1 1.39 69.2 100.0 100.0 We1ght Percent Percent Product Percent Mo lnsol. Mo lnsol. gg g Head 100.00 10.99 68.6 100.0 100.0 Concentrate 52.51 18.82 55.6 89.9 42.6 Tailing 47.49 2.34 82.9 10.1 57.3

EXAMPLE 13 The procedure of example 2 is repeated employing a EXAMPLE l0 pulp density of about 5% solids, MnCl (16 pounds per A sample of the composite desbribed in example 1 ton of solids) 1n place of ZnSO and sodium s1l1cate (7.5 pounds per ton of sol1ds) with good results. was sub ected to the pulpmg procedure described 1n example l. The pulp was then agitated with a quantityof EXAMPLE l4 fi cofrespongmg to f g 5 ton The procedure of example 9 is repeated with a pulp of sohds we mmutes' quantity 0 so Cate density of about 1% solids and the water-soluble calcorrespondmg to 7.5 pounds per ton of solids was then cium Salts of boron (3 pounds per ton of sofids) with added to the pulp. The pulp was then sub ected to flota- Similar results tion as described in example 1. The results are presented in the following table. EXAMPLE 15 Another sample of a low grade molybdenite concen- D'! trate that contained a substantial portion of a hydroweight Percent $2 3?" phobic talc was made into a dilute pulp of approxi- Product Percent M0 1150]. M0 111561. mately 5% SOlIdS 1n water at ambient temperature in a Head 10000 I H 7 69'] I000 I000 laboratory flotation cell. This pulp had apH of 8.3 The Concentrate 34.09 29.66 41.7 90.4 20.6 sample so prepared was then agitated w1th a quantity of zinc sulfate corresponding to six pounds per ton of solids for about 30 minutes. The pH of this admixture was measured and found to be 6.8. Thereafter one pound per ton of solids of NaOH was mixed with the pulp so treated resulting in a pH of 7.1. Thereafter eight pounds per ton of potassium ferrocyanide was mixed with the aforementioned pulp containing zinc sulfate and NaOH. The resulting admixture had a pH of 8.2. The said admixture was immediately subjected to froth flotation and the froth removed for five minutes during which a concentrate was separated with results as follows.

Percent Mo Recovered in Concentrate Percent Mo ln Tail Concentrate Percent Weight in Concentrate Head Percent Mo Recovered in Concentrate Percent M in Tail Concentrate Percent Weight in Concentrate Head As a result of repeating the above experiment substituting various metals for zinc, it was observed that no effective separation of talc from a molybdenite bearing concentrate was obtained.

EXAMPLE 16 Method of Determining Acid Insoluble Percentage in Molybdenite Containing Ore or Concentrate. Procedure:

1. Weight 0.5 gram of molybdenum concentrate sample and transfer to a 400 ml. beaker. Add 25 ml. of concentrated nitric acid, place on hot plate and warm slightly. Add approximately A; teaspoon potassium chlorate, place watch glasses on beakers and take to near dryness.

2. Add 10 ml. of concentrated hydrochloric acid and again place on the hot plate and take to near dryness.

3. Add 10 ml. of concentrated hydrochloric acid again and approximately 50 ml. of distilled water. Place on the hot plate, bring to a boil and boil for 5-10 minutes.

4. Remove from hot plate and filter through cm. Whatman No. 40 (ashless) filter paper. Wash several times with hot distilled water.

5. Place residue in a clay annealing cup and ash in a muffle furnace.

6. Cool and weigh.

Calculation:

Wt. insol in grams 100 71 Acid lnsol wt. sample in grams a. Water soluble metallic salt ofa weak base of which the cation is selected from the class consisting of aluminum, cadmium, chromium, cobalt, copper, iron, calcium, magnesium, manganese, nickel and zinc, and a strong acid selected from the class consisting of hydrochloric acid, nitric acid and sulfuric acid affording the anions chloride, nitrate and sulfate, and

b. Sodium silicate or potassium silicate.

a. Water soluble metallic salt of a weak base of which the cation is selected from the class consisting of aluminum, chromium, copper, manganese, and zinc, and a strong acid selected from the class consisting of hydrochloric acid, nitric acid and sulfuric acid affording the anions chloride, nitrate and sulfate, and

b. Sodium hydrogen carbonate, potassium hydrogen carbonate, or ammonium hydrogen carbonate.

a. Water soluble metallic salt of a weak base of which the cation is selected from the class consisting of aluminum, chromium, manganese, and zinc, and a strong acid selected from the class consisting of hydrochloric acid, nitric acid and sulfuric acid affording the anions chloride, nitrate and sulfate, and

b. Water soluble sodium monohydrogen orthophosphate, potassium monohydrogen orthophosphate, or ammonium monohydrogen orthophosphate.

a. Water soluble metallic salt of a weak base of which the cation is selected from the class consisting of aluminum, cobalt, copper, manganese, and zinc, and a strong acid selected from the class consisting of hydrochloric acid, nitric acid and sulfuric acid affording the anions chloride, nitrate and sulfate, and

b. Water soluble sodium borate, potassium borate or ammonium borate.

a. Water soluble metallic salt of a weak base of which the cation is selected from the class consisting of aluminum, copper, and zinc, and a strong acid selected from the class consisting of hydrochloric acid, nitric acid and sulfuric acid affording the anion chloride, nitrate and sulfate, and

b. Water soluble sodium orthophosphate, potassium orthophosphate or ammonium orthophosphate.

a. Water soluble zinc chloride, zinc nitrate, or zinc sulfate, and I b. Sodium carbonate, potassium carbonate, ammonium carbonate, sodium ferrocyanide, potassium ferrocyanide or ammonium ferrocyanide.

a. Water soluble zinc chloride, zinc nitrate, or zinc sulfate, and

b. Sodium silicate or potassium silicate.

Thus, having described the invention, what is claimed 1. A method of separating ore or concentrate having molybdenite and a substantial amount of hydrophobic silicate containing magnesium by froth flotation to obtain a molybdenite enriched concentrate and hydrophobic silicate enriched tailings, which method consists essentially of:

l forming a dual agent treated aqueous pulp of said ore or concentrate, said dual agent consisting essentially of I. (a) water soluble metallic salt of a weak base and a strong acid, and

9 (b) water soluble alkali metal, water soluble alkaline earth metal or water soluble ammonium salt of a weak acid selected from the group consisting of boron acids, carbonic acids, acids of phosphorous and silicic acids; or II. (a) water soluble zinc salt of a strong acid, and (b) water soluble salt of hydroferrocyanic acid, and 2. subjecting said dual agent treated aqueous pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and hydrophobic silicate is selectively depressed into the tailings from said froth flotation separation.

2. The method of claim 1 wherein said treating of l) is carried out by adding said metallic salt of (I) (a) and (II) (a) to said aqueous pulp prior to the addition of said salt of (I) (b) and (II) (b), as the case may be.

3. The method of claim 1 wherein said treating of l) is carried out by adding said salt of (I) (b) and (II) (b) to said aqueous pulp prior to the addition of said metallic salt of (I) (a) and (II) (a), as the case may be.

4. The method of claim 1 wherein each component of said dual agent of (I) and (II), as the case may be, is added substantially simultaneously to. said aqueous pulp.

5. A method of separating ore or concentrate having molybdenite and a substantial amount of hydrophobic silicate containing magnesium by froth flotation to obtain a molybdenite enriched concentrate and hydrophobic silicate enriched tailings, which method consists essentially of:

1. forming a dual agent treated aqueous pulp of said ore or concentrate,

where the treating agent consists essentially of I (a). water soluble metallic salt of a weak base of which the cation is selected from the class consisting. of aluminum, cadmium, chromium, cobalt, copper, calcium, magnesium, iron, manganese, nickel and zinc, and a strong acid selected from the class consisting of hydrochloric acid, hydrofluoric acid, nitric acid and sulfuric acid affording the anions chloride, fluoride, nitrate and sulfate, and

I (b). water soluble alkali metal, water soluble alkaline earth metal, or water soluble ammonium salt of weak acid selected from the class consisting of boron acids, carbonic acid, acids of phosphorous, and silicic acid; or I II (a). water soluble zinc chloride, zinc fluoride,

zinc nitrate, or zinc sulfate, and

II (b). water soluble alkali metal, water soluble alkaline earth metal, or water soluble ammonium salt of hydroferrocyanic acid; and

2. subjecting said dual agent treated aqueous pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and hydrophobic silicate is selectively depressed into the tailings from said froth flotation separation.

6. The method of claim 5 wherein said aqueous pulp has a pulp density of from about 1% to 45% solids.

7. A method of separating ore or concentrate having molybdenite and a substantial amount of a hydrophobic silicate talc containing magnesium by froth flotation to obtain a molybdenite enriched concentrate and hydrophobic silicate talc enriched tailings, which method consists essentially of:

l. forming a dual agent treated aqueous pulp of said ore or concentrate,

10 where the treating agent consists essentially of aluminum sulfate and sodium silicate, and

2. subjecting said dual treated aqueous pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and hydrophobic silicate tale is selectively depressed into the tailings from said froth flotation separation.

8. A method of separating ore or concentrate having molybdenite and a substantial amount of hydrophobic silicate containing magensium by froth flotation to obtain a molybdenite enriched concentrate and hydrophobic silicate enriched tailings, which method consists essentially of:

l. forming a dual agent treated aqueous pulp of said ore or concentrate, where the treating agent consists essentially of I (a). water soluble metallic salt of a weak base of which the cation is selected from the class consisting of aluminum, cadmium, chromium, cobalt, copper, calcium, magnesium, iron, manganese, nickel and zinc, and a strong acid selected from the class consisting of hydrochloric acid, hydrofluoric acid, nitric acid and sulfuric acid affording the anions chloride, fluoride, nitrate and sulfate, and

l (b). water soluble alkali metal, water soluble alkaline earth metal, or water soluble ammonium salt of weak acid selected from the class consisting of boron acids, carbonic acid, acids of phosphorus, and silicic acid; or

II (a). water soluble zinc chloride, zinc fluoride,

zinc nitrate, or zinc sulfate, and

II (b). water soluble alkali metal, water soluble alkaline earth metal, or water soluble ammonium salt of hydroferrocyanic acid; and

where said treating is carried out by adding said metallic salt of (I) (a) and (II) (a) to said aqueous pulp to condition said pulp prior to the addition of said salt of (I) (b) and (II) (b), as the case may be, and

2. subjecting said dual agent treated aqueous pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and hydrophobic silicate is selectively depressed into the tailings from said froth flotation separation.

9. A method of separating ore or concentrate having molybdenite and a substantial amount of hydrophobic silicate containing magnesium by froth flotation to obtain a molybdenite enriched concentrate and hydrophobic silicate enriched tailings, which method consists essentially of:

l. forming a dual agent treated aqueous pulp of said ore or concentrate, where the treating agent consists essentially of (I) (a). water soluble metallic salt of a weak base of which the cation is selected from the class consisting of aluminum, cadmium, chromium, cobalt, copper, calcium, magnesium, iron, manganese, nickel and zinc, and a strong acid selected from the class consisting of hydrochloric acid, hydrofluoric acid, nitric acid and sulfuric acid affording the anions chloride, fluoride, nitrate and sulfate, and

(I) (b). water soluble alkali metal, water soluble alkaline earth metal, or water soluble ammonium salt of weak acid selected from the class consisting of boron acids, carbonic acid, acids of phorphorus, and silicic acid; or

ll (a). water soluble zinc chloride, zinc fluoride,

zinc nitrate, or zinc sulfate, and

ll (b). water soluble alkali metal, water soluble alkaline earth metal, or water soluble ammonium salt of hydroferrocyanic acid; and

where said aqueous pulp is treated with between about 1 and 30 pounds per ton of pulp solids of said metallic salt of (I) (a) and (ll) (a) and between about 1 and 45 pounds per ton of pulp solids of said salt of (I) (b) and (II) (b) as the case may be, and

2. subjecting said dual agent treated aqueous pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and hydrophobic silicate is selectively depressed into the tailings from said froth flotation separation.

10. A method of separating ore or concentrate having molybdenite and a substantial amount of hydrophobic silicate containing magnesium by froth flotation to obtain a molybdenite enriched concentrate and hydrophobic silicate enriched tailings, which method consists essentially of:

l. forming a dual agent treated aqueous pulp of said ore or concentrate,

where the treating agent consists essentially of a. water soluble metallic salt of a weak base of which the cation is selected from the class consisting of aluminum, cadmium, chromium, cobalt, copper, calcium, magnesium, iron, manganese, nickel and zinc, and a strong acid selected from the class consisting of hydrochloric acid, nitric acid and sulfuric acid affording the anions chloride, nitrate and sulfate, and

b. sodium silicate or potassium silicate and 2. subjecting said dual agent treated aqueous pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and hydrophobic silicate is selectively depressed into the tailings from said froth flotation separation.

11. A method of separating ore or concentrate having molybdenite and a substantial amount of hydrophobic silicate containing magensium by froth flotation to obtain a molybdenite enriched concentrate and hydrophobic silicate enriched tailings, which method consists essentially of:

l. forming a dual agent treated aqueous pulp of said ore or concentrate,

where the treating agent consists essentially of a. water soluble metallic salt of a weak base of which the cation is selected from the class consisting of aluminum, chromium, copper, manganese, and zinc, and a strong acid selected from the class consisting of hydrochloric acid, nitric acid and sulfuric acid affording the anions chloride, nitrate and sulfate, and

b. sodium hydrogen carbonate, potassium hydrogen carbonate, or ammonium hydrogen carbonate, and

2. I subjecting said dual agent treated aqueous pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and hydrophobic silicate is selectively depressed into the tailings from said froth flotation separation.

12. A method of separating ore or concentrate having molybde nite and a substantial amount of hydrophobic silicate containing magnesium by froth flotation to obtain a molybdenite enriched concentrate and hydro- 12 phobic silicate enriched tailings, which method consists essentially of:

l. forming a dual agent treated aqueous pulp of said ore or concentrate,

where the treating agent consists essentially of a. water soluble metallic salt of a weak base of which the cation is selected from the class consisting of aluminum, chromium, manganese, and zinc, and a strong acid selected from the class consisting of hydrochloric acid, nitric acid and sulfuric acid affording the anions chloride, nitrate and sulfate, and

b. water soluble sodium monohydrogen orthophosphate, potassium monohydrogen orthophosphate, or ammonium monohydrogen orthophosphate, and

2. subjecting said dual agent treated aqueous pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and hydrophobic silicate is selectively depressed into the tailings from said froth flotation separation. 13.-A method of separating ore or concentrate having molybdenite and a substantial amount of hydrophobic silicate containing magnesium by froth flotation to obtain a molybdenite enriched concentrate and hydrophobic silicate enriched tailings, which method consists essentially of:

l. forming a dual agent treated aqueous pulp of said ore or concentrate, where the treating agent consists essentially of a. water soluble metallic salt of a weak base of which the cation is selected from the class consisting of aluminum, cobalt, copper, manganese, and zinc, and a strong acid selected from the class consisting of hydrochloric acid, nitric acid and sulfuric acid affording the anions choloride, nitrate and sulfate, and

b. water soluble sodium borate, potassium borate or ammonium borate, and

2. subjecting said dual agent treated aqueous pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and hydrophobic silicate is selectively depressed into the tailings from said froth flotation separation.

45 14. A method of separating ore or concentrate having molybdenite and a substantial amount of hydrophobic silicate containing magnesium by froth flotation to obtain a molybdenite enriched concentrate and hydrophobic silicate enriched tailings, which method consists 50 essentially of:

l. forming a dual agent treated aqueous pulp of said ore or concentrate,

where the treating agent consists essentially of a. water soluble metallic salt of a weak base of which the cation is selected from the class consisting of aluminum, copper, and zinc, and a strong acid selected from the class consisting of hydrochloric acid, nitric acid and sulfuric acid affording the anions chloride, nitrate and sulfate, and

b. water soluble sodium orthophosphate, potassium orthophosphate, or ammonium orthophosphate, and

2. subjecting said dual agent treated aqueous pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and hydrophobic silicate is selectively depressed into the tailings from said froth flotation separation.

13 15. A method of separating ore or concentrate having molybdenite and a substantial amount of hydrophobic silicate containing magnesium by froth flotation to obtain a molybdenite enriched concentrate and hydrophobic silicate enriched tailings, which method consists essentially of: v

l. formina a dual agent treated aqueous pulp of said ore or concentrate, where the treating agent consists essentially of a. water soluble zinc chloride, zinc nitrate or zinc sulfate, and

b. sodium carbonate, potassium carbonate, ammonium carbonate, sodium ferrocyanide, potassium ferrocyanide or ammonium ferrocyanide, and

2. subjecting said dual agent treated aqueous pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and hydrophobic silicate is selectively depressed into the tailings from said froth flotation separation.

16. A method of separating ore or concentrate having molybdenite and a substantial amount of hydrophobic silicate containing magnesium by froth flotation to obtain a molybdenite enriched concentrate and hydrophobic silicate enriched tailings, which method consists essentially of:

l. forming a dual agent treated aqueous pulp of said ore or concentrate,

where the treating agent consists essentially of a. water soluble zinc chloride, zinc nitrate, or zinc sulfate, and b. sodium silicate or potassium silicate, and

2. subjecting said dual agent treated aqueous pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and hydrophobic silicate is selectively depressed into the tailings from said froth flotation separation.

17. A method of separating a charge of molybdenite concentrate containing molybdenite as the major metal value, talc and other acid insoluble minerals which method consists essentially of:

l. forming an aqueous pulp to said concentrate;

2. adding zinc sulfate to said aqueous pulp and mixing for a conditioning time followed by the addition of sodium silicate, and

3. subjecting said admixture to froth flotation separation whereby a molybdenite enriched concentrate product is floated and tale is selectively depressed 14 into the tailings from said froth flotation separation.

18. The method of claim 17 wherein said charge concentrate contains about 18% molybdenite, 4% chalcopyrite, 5% pyrite and 69% acid insoluble minerals of which a major portion is a hydrophobic talc,

sodium silicate is added in an amount of about 7.5

pounds per ton of solids and zinc sulfate is added in an amount of about 16 pounds per ton of solids; and the conditioning time is about 30 minutes.

19. A method of separating molybdenite concentrate containing molybdenite as the major metal value, talc and other acid insoluble minerals, which method consists essentially of:

l. forming an aqueous pulp of said concentrate;

2. conditioning said aqueous pulp with aluminum sulfate;

3. adding to said conditioned pulp sodium acid carbonate; and

4. subjecting said conditioned aqueous pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and talc is selectively depressed into the tailings from said froth flotation separation.

20. The method of claim 19 wherein said aluminum sulfate is added in an amount of about l pound per ton of solids and said carbonate is added in an amount of about 7.5 pounds per ton of solids.

21. A method of separating molybdenite concentrate containing molybdenite as the major metal value, talc and other acid insoluble minerals, which method consists essentially of:

l. forming an aqueous pulp of said concentrate;

2. conditioning said aqueous pulp with zinc sulfate;

3. adding to said conditioned pulp potassium ferrocyanide; and

4. subjecting said sulfate-ferrocyanide treated pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and tale is selectively depressed into the tailings from said froth flotation separation.

22. The method of claim 21 wherein said zinc sulfate is added in an amount of about 6 pounds per ton of solids and said ferrocyanide is added in an amount of about 8 pounds per ton of solids. 

1. FORMING A DUAL AGENT TREATED AQUEOUS PULP OF SAID ORE OR CONCENTRATE, SAID DUAL AGENT CONSISTING ESSENTIALLY OF I. (A) WATER SOLUBLE METALLIC SALT OF A WEAK BASE AND A STRONG ACID, AND (B) WATER SOLUBLE ALKALI METAL, WATER SOLUBLE ALKALINE EARTH METAL OR WATER SOLUBLE AMMONIUM SALT OF A WEAK ACID SELECTED FROM THE GROUP CONSISTING OF BORON ACIDS, CARBONIC ACIDS, ACIDS OR PHOSPHOROUS AND SILICIC ACIDS; OR II. (A) WATER SOLUBLE ZINC SALT OF A STRONG ACID, AND (B) WATER SOLUBLE SALT OF HYDROFERROCYANIC ACID, AND
 1. A METHOD OF SEPARATING ORE OR CONCENTRATE HAVING MOLYBDENITE AND A SUBSTANTIAL AMOUNT OF HYDROPHOBIC SILICATE CONTAINING MAGNESIUM BU FROTH FLOTATION TO OBTAIN A MOLYNDENITE ENRICHED CONCENTRATE AND HYDROPHROBIC SILICATE ENRICHED TAILINGS, WHICH METHOD CONSISTS ESSENTIALLY OF:
 2. SUBJECTING SAID DUAL AGENT TREATED AQUEOUS PULP TO FROTH FLOTATION SEPARATION WHEREBY A MOLYBDENITE ENRICHED CONCENTRATE IS FLOATED AND HYDROPHOBIC SILICATE IS SELECTIVELY DEPRESSED INTO THE TAILINGS FROM SAID FROTH FLOTATION SEPARATION.
 2. subjecting said dual agent treated aqueous pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and hydrophobic silicate is selectively depressed into the tailings from said froth flotation separation.
 2. subjecting said dual agent treated aqueous pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and hydrophobic silicate is selectively depressed into the tailings from said froth flotation separation.
 2. subjecting said dual agent treated aqueous pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and hydrophobic silicate is selectively depressed into the tailings from said froth flotation separation.
 2. subjecting said dual agent treated aqueous pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and hydrophobic silicate is selectively depressed into the tailings from said froth flotation separation.
 2. l subjecting said dual agent treated aqueous pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and hydrophobic silicate is selectively depressed into the tailings from said froth flotation separation.
 2. subjecting said dual agent treated aqueous pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and hydrophobic silicate is selectively depressed into the tailings from said froth flotation separation.
 2. subjecting said dual agent treated aqueous pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and hydrophobic silicate is selectively depressed into the tailings from said froth flotation separation.
 2. subjecting said dual treated aqueous pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and hydrophobic silicate talc is selectively depressed into the tailings from said froth flotation separation.
 2. conditioning said aqueous pulp with zinc sulfate;
 2. conditioning said aqueous pulp with aluminum sulfate;
 2. subjecting said dual agent treated aqueous pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and hydrophobic silicate is selectively depressed into the tailings from said froth flotation separation.
 2. The method of claim 1 wherein said treating of (1) is carried out by adding said metallic salt of (I) (a) and (II) (a) to said aqueous pulp prior to the addition of said salt of (I) (b) and (II) (b), as the case may be.
 2. subjecting said dual agent treated aqueous pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and hydrophobic silicate is selectively depressed into the tailings from said froth flotation separation.
 2. adding zinc sulfate to said aqueous pulp and mixing for a conditioning time followed by the addition of sodium silicate, and
 2. subjecting said dual agent treated aqueous pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and hydrophobic silicate is selectively depressed into the tailings from said froth flotation separation.
 2. subjecting said dual agent treated aqueous pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and hydrophobic silicate is selectively depressed into the tailings from said froth flotation separation.
 3. The method of claim 1 wherein said treating of (1) is carried out by adding said salt of (I) (b) and (II) (b) to said aqueous pulp prior to the addition of said metallic salt of (I) (a) and (II) (a), as the case may be.
 3. subjecting said admixture to froth flotation separation whereby a molybdenite enriched concentrate product is floated and talc is selectively depressed into the tailings from said froth flotation separation.
 3. adding to said conditioned pulp sodium acid carbonate; and
 3. adding to said conditioned pulp potassium ferrocyanide; and
 4. subjecting said conditioned aqueous pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and talc is selectively depressed into the tailings from said froth flotation separation.
 4. subjecting said sulfate-ferrocyanide treated pulp to froth flotation separation whereby a molybdenite enriched concentrate is floated and talc is selectively depressed into the tailings from said froth flotation separation.
 4. The method of claim 1 wherein each component of said dual agent of (I) and (II), as the case may be, is added substantially simultaneously to said aqueous pulp.
 5. A method of separating ore or concentrate having molybdenite and a substantial amount of hydrophobic silicate containing magnesium by froth flotation to obtain a molybdenite enriched concentrate and hydrophobic silicate enriched tailings, which method consists essentially of:
 6. The method of claim 5 wherein said aqueous pulp has a pulp density of from about 1% to 45% solids.
 7. A method of separating ore or concentrate having molybdenite and a substantial amount of a hydrophobic silicate talc containing magnesium by froth flotation to obtain a molybdenite enriched concentrate and hydrophobic silicate talc enriched tailings, which method consists essentially of:
 8. A method of separating ore or concentrate having molybdenite and a substantial amount of hydrophobic silicate containing magensium by froth flotation to obtain a molybdenite enriched concentrate and hydrophobic silicate enriched tailings, which method consists essentially of:
 9. A method of separating ore or concentrate having molybdenite and a substantial amount of hydrophobic silicate containing magnesium by froth flotation to obtain a molybdenite enriched concentrate and hydrophobic silicate enriched tailings, which method consists essentially of:
 10. A method of separating ore or concentrate having molybdenite and a substantial amount of hydrophobic silicate containing magnesium by froth flotation to obtain a molybdenite enriched concentrate and hydrophobic silicate enriched tailings, which method consists essentially of:
 11. A method of separating ore or concentrate having molybdenite and a substantial amount of hydrophobic silicate containing magensium by froth flotation to obtain a molybdenite enriched concentrate and hydrophobic silicate enriched tailings, which method consists essentially of:
 12. A method of separating ore or concentrate having molybdenite and a substantial amount of hydrophobic silicate containing magnesium by froth flotation to obtain a molybdenite enriched concentrate and hydrophobic silicate enrichEd tailings, which method consists essentially of:
 13. A method of separating ore or concentrate having molybdenite and a substantial amount of hydrophobic silicate containing magnesium by froth flotation to obtain a molybdenite enriched concentrate and hydrophobic silicate enriched tailings, which method consists essentially of:
 14. A method of separating ore or concentrate having molybdenite and a substantial amount of hydrophobic silicate containing magnesium by froth flotation to obtain a molybdenite enriched concentrate and hydrophobic silicate enriched tailings, which method consists essentially of:
 15. A method of separating ore or concentrate having molybdenite and a substantial amount of hydrophobic silicate containing magnesium by froth flotation to obtain a molybdenite enriched concentrate and hydrophobic silicate enriched tailings, which method consists essentially of:
 16. A method of separating ore or concentrate having molybdenite and a substantial amount of hydrophobic Silicate containing magnesium by froth flotation to obtain a molybdenite enriched concentrate and hydrophobic silicate enriched tailings, which method consists essentially of:
 17. A method of separating a charge of molybdenite concentrate containing molybdenite as the major metal value, talc and other acid insoluble minerals which method consists essentially of:
 18. The method of claim 17 wherein said charge concentrate contains about 18% molybdenite, 4% chalcopyrite, 5% pyrite and 69% acid insoluble minerals of which a major portion is a hydrophobic talc, sodium silicate is added in an amount of about 7.5 pounds per ton of solids and zinc sulfate is added in an amount of about 16 pounds per ton of solids; and the conditioning time is about 30 minutes.
 19. A method of separating molybdenite concentrate containing molybdenite as the major metal value, talc and other acid insoluble minerals, which method consists essentially of:
 20. The method of claim 19 wherein said aluminum sulfate is added in an amount of about 1 pound per ton of solids and said carbonate is added in an amount of about 7.5 pounds per ton of solids.
 21. A method of separating molybdenite concentrate containing molybdenite as the major metal value, talc and other acid insoluble minerals, which method consists essentially of:
 22. The method of claim 21 wherein said zinc sulfate is added in an amount of about 6 pounds per ton of solids and said ferrocyanide is added in an amount of about 8 pounds per ton of solids. 